Five galaxies as seen with MUSE on ESO’s VLT at several wavelengths of light
NGC 4303 as seen with MUSE on ESO’s VLT at several wavelengths of light
NGC 4254 as seen with MUSE on ESO’s VLT at several wavelengths of light
NGC 3627 as seen with MUSE on ESO’s VLT at several wavelengths of light
NGC 1087 as seen with MUSE on ESO’s VLT at several wavelengths of light
NGC 1300 as seen with MUSE on ESO’s VLT at several wavelengths of light
NGC 4303 as seen with the VLT and ALMA at several wavelengths of light
NGC 4254 as seen with the VLT and ALMA at several wavelengths of light
NGC 3627 as seen with the VLT and ALMA at several wavelengths of light
NGC 1087 as seen with the VLT and ALMA at several wavelengths of light
NGC 1300 as seen with the VLT and ALMA at several wavelengths of light
Videos
Cosmic fireworks reveal newborn stars (ESOcast Light 239)
Multiple views of the galaxy NGC 4303 as seen with the VLT and ALMA (with annotations)
Multiple views of the galaxy NGC 4254 as seen with the VLT and ALMA
Multiple views of the galaxy NGC 3627 as seen with the VLT and ALMA
Multiple views of the galaxy NGC 1087 as seen with the VLT and ALMA
Multiple views of the galaxy NGC 1300 as seen with the VLT and ALMA
Multiple views of the galaxy NGC 4303 as seen with the VLT and ALMA
Image Comparisons
A team of astronomers has released new
observations of nearby galaxies that resemble colourful cosmic
fireworks. The images, obtained with the European Southern Observatory’s
Very Large Telescope (ESO’s VLT), show different components of the
galaxies in distinct colours, allowing astronomers to pinpoint the
locations of young stars and the gas they warm up around them. By
combining these new observations with data from the Atacama Large
Millimeter/submillimeter Array (ALMA), in which ESO is a partner, the
team is helping shed new light on what triggers gas to form stars.
Astronomers know that stars are born in clouds of gas, but
what sets off star formation, and how galaxies as a whole play into it,
remains a mystery. To understand this process, a team of researchers has
observed various nearby galaxies with powerful telescopes on the ground
and in space, scanning the different galactic regions involved in
stellar births.
“For the first time we are resolving individual units
of star formation over a wide range of locations and environments in a
sample that well represents the different types of galaxies,” says
Eric Emsellem, an astronomer at ESO in Germany and lead of the VLT-based
observations conducted as part of the Physics at High Angular
resolution in Nearby GalaxieS (PHANGS) project. “We can directly
observe the gas that gives birth to stars, we see the young stars
themselves, and we witness their evolution through various phases.”
Emsellem, who is also affiliated with the University of
Lyon, France, and his team have now released their latest set of
galactic scans, taken with the Multi-Unit Spectroscopic Explorer (MUSE)
instrument on ESO’s VLT in the Atacama Desert in Chile. They used MUSE
to trace newborn stars and the warm gas around them, which is
illuminated and heated up by the stars and acts as a smoking gun of
ongoing star formation.
The new MUSE images are now being combined with
observations of the same galaxies taken with ALMA and released earlier
this year. ALMA, which is also located in Chile, is especially well
suited to mapping cold gas clouds — the parts of galaxies that provide
the raw material out of which stars form.
By combining MUSE and ALMA images astronomers can examine
the galactic regions where star formation is happening, compared to
where it is expected to happen, so as to better understand what
triggers, boosts or holds back the birth of new stars. The resulting
images are stunning, offering a spectacularly colourful insight into
stellar nurseries in our neighbouring galaxies.
“There are many mysteries we want to unravel,” says Kathryn Kreckel from the University of Heidelberg in Germany and PHANGS team member. “Are
stars more often born in specific regions of their host galaxies — and,
if so, why? And after stars are born how does their evolution influence
the formation of new generations of stars?”
Astronomers will now be able to answer these questions
thanks to the wealth of MUSE and ALMA data the PHANGS team have
obtained. MUSE collects spectra — the “bar codes” astronomers scan to
unveil the properties and nature of cosmic objects — at every single
location within its field of view, thus providing much richer
information than traditional instruments. For the PHANGS project, MUSE
observed 30 000 nebulae of warm gas and collected about 15 million
spectra of different galactic regions. The ALMA observations, on the
other hand, allowed astronomers to map around 100 000 cold-gas regions
across 90 nearby galaxies, producing an unprecedentedly sharp atlas of stellar nurseries in the close Universe.
In addition to ALMA and MUSE, the PHANGS project also
features observations from the NASA/ESA Hubble Space Telescope. The
various observatories were selected to allow the team to scan our
galactic neighbours at different wavelengths (visible, near-infrared and
radio), with each wavelength range unveiling distinct parts of the
observed galaxies. “Their combination allows us to probe the various
stages of stellar birth — from the formation of the stellar nurseries
to the onset of star formation itself and the final destruction of the
nurseries by the newly born stars — in more detail than is possible with
individual observations,” says PHANGS team member Francesco Belfiore from INAF-Arcetri in Florence, Italy. "PHANGS
is the first time we have been able to assemble such a complete view,
taking images sharp enough to see the individual clouds, stars, and
nebulae that signify forming stars."
The work carried out by the PHANGS project will be further
honed by upcoming telescopes and instruments, such as NASA’s James Webb
Space Telescope. The data obtained in this way will lay further
groundwork for observations with ESO’s future Extremely Large Telescope
(ELT), which will start operating later this decade and will enable an
even more detailed look at the structures of stellar nurseries.
“As amazing as PHANGS is, the resolution of the maps
that we produce is just sufficient to identify and separate individual
star-forming clouds, but not good enough to see what’s happening inside
them in detail,” pointed out Eva Schinnerer, a research group
leader at the Max Planck Institute for Astronomy in Germany and
principal investigator of the PHANGS project, under which the new
observations were conducted. “New observational efforts by our team
and others are pushing the boundary in this direction, so we have
decades of exciting discoveries ahead of us.”
More Information
The international PHANGS team is composed of over 90
scientists ranging from Master students to retirees working at 30
institutions across four continents. The MUSE data reduction working
group within PHANGS is being led by Eric Emsellem (European Southern
Observatory, Garching, Germany and Centre de Recherche Astrophysique de
Lyon, Université de Lyon, ENS de Lyon, Saint-Genis Laval, France) and
includes Francesco Belfiore (INAF Osservatorio Astrofisico di Arcetri,
Florence, Italy), Guillermo Blanc (Carnegie Observatories, Pasadena,
US), Enrico Congiu (Universidad de Chile, Santiago, Chile and Las
Campanas Observatory, Carnegie Institution for Science, Atacama Region,
Chile), Brent Groves (The University of Western Australia, Perth,
Australia), I-Ting Ho (Max Planck Institute for Astronomy, Heidelberg,
Germany [MPIA]), Kathryn Kreckel (Heidelberg University, Heidelberg,
Germany), Rebecca McElroy (Sydney Institute for Astronomy, Sydney,
Australia), Ismael Pessa (MPIA), Patricia Sanchez-Blazquez (Complutense
University of Madrid, Madrid, Spain), Francesco Santoro (MPIA), Fabian
Scheuermann (Heidelberg University, Heidelberg, Germany) and Eva
Schinnerer (MPIA).
Go to the ESO public image archive to see a sample of PHANGS images.
ESO is the foremost intergovernmental
astronomy organisation in Europe and the world’s most productive
ground-based astronomical observatory by far. It has 16 Member States:
Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany,
Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden,
Switzerland and the United Kingdom, along with the host state of Chile
and with Australia as a Strategic Partner. ESO carries out an
ambitious programme focused on the design, construction and operation of
powerful ground-based observing facilities enabling astronomers to make
important scientific discoveries. ESO also plays a leading role in
promoting and organising cooperation in astronomical research. ESO
operates three unique world-class observing sites in Chile: La Silla,
Paranal and Chajnantor. At Paranal, ESO operates the Very Large
Telescope and its world-leading Very Large Telescope Interferometer as
well as two survey telescopes, VISTA working in the infrared and the
visible-light VLT Survey Telescope. Also at Paranal ESO will host and
operate the Cherenkov Telescope Array South, the world’s largest and
most sensitive gamma-ray observatory. ESO is also a major partner in two
facilities on Chajnantor, APEX and ALMA, the largest astronomical
project in existence. And on Cerro Armazones, close to Paranal, ESO is
building the 39-metre Extremely Large Telescope, the ELT, which will
become “the world’s biggest eye on the sky”.
Links
Contacts
Eric Emsellem
European Southern Observatory
Garching bei München, Germany
Tel: +49 89 3200 6914
Email: eric.emsellem@eso.org
Eva Schinnerer
Max Planck Institute for Astronomy
Heidelberg, Germany
Tel: +49 6221 528 294
Email: schinner@mpia.de
Kathryn Kreckel
Astronomisches Recheninstitut, Zentrum für Astronomie, Universität Heidelberg
Heidelberg, Germany
Email: kathryn.kreckel@uni-heidelberg.de
Francesco Belfiore
INAF Osservatorio Astrofisico di Arcetri
Florence, Italy
Email: francesco.belfiore@inaf.it
Bárbara Ferreira
ESO Media Manager
Garching bei München, Germany
Tel: +49 89 3200 6670
Cell: +49 151 241 664 00
Email: press@eso.org
Source: ESO/News
